高等数学——《第二章》极限与连续(16)

1 n(n 1) 1 n( n 1)(n 2) 1 xn 1 n 2 3 n 1 2 1 2 3 n n n( n 1)(n 2) 2 1 1 n 1 2 n n 1 1 1 1 2 1 1 (1 ) (1 )(1 ) 2 n 3! n n 1 1 2 n 1 (1 )(1 ) (1 ) n! n n n

1 1 1 1 2 xn 1 1 1 (1 ) (1 )(1 ) 2 n 1 3! n 1 n 1 1 1 2 n 1 1 (1 )(1 ) (1 ) n! n 1 n 1 n 1 (n 1) n 1